1945-1947: Mach Buster
By Air Force Flight Test Center History Office, Dr. James Young, Chief Historian
After a short stint as a flight instructor at Perrin Field, TX, Yeager was assigned as assistant maintenance officer in the Fighter Section of the Flight Test Division at Wright Field, OH. He was at the right place, at the right time. Wright Field was the center of Army Air Forces R and D and, since it was his job to check out all aircraft coming out of maintenance, he got to fly almost every fighter on the flight line. He demonstrated such exceptional skill that he was selected to fly in air shows and, in September 1945, he made his first trip to Muroc Army Air Field (now Edwards AFB) where he flew accelerated service trials on the new P-80A Shooting Star, America’s first operational jet fighter.
Yeager in the cockpit of a P-80A at Wright Field (note his headgear, the crown of a tank corpsman’s helmet snapped onto his original leather flying cap).
The P-47D was one of the first aircraft Yeager checked out in after arriving at Wright Field.
Considered the father of modern Air Force flight test, Col Albert Boyd was chief of the Flight Test Division. Tough and absolutely unyielding in his standards, he was trying to build a cadre of test pilots that could set industry-wide standards for the profession. Under his scrutiny, only the very best pilots were selected to enter the new test pilot school at Wright Field. After closely observing and flying with Yeager, Boyd handpicked him for the school in January 1946.
Col Albert Boyd, chief of the Flight Test Division at Wright Field, would subsequently serve as the first commander of the Air Force Flight Test Center at Edwards AFB.
New P-80As on the ramp during accelerated service trials at Muroc Army Air Field, October 1945.
A new P-80A Shooting Star in test over Muroc Army Air Field, October 1945.
With only a high school education, he was challenged by the advanced academics but managed to graduate.“Because of my flying ability,” he later explained “they took mercy on my academics.” In June 1947 Colonel Boyd made one of the most important decisions of his career when he chose one of his most junior test pilots to attempt to become the first person to exceed the speed of sound in the rocket-powered Bell XS-1. He chose Yeager because he considered him the best “instinctive” pilot he had ever seen and he had demonstrated an extraordinary capacity to remain calm and focused in stressful situations. The X-1 program certainly promised to be stressful; many experts believed the so-called “sound barrier” was impenetrable. Yeager and the rest of the small Air Force test team met at Muroc in late July.
After three glide flights in the Bell XS-1 rocket research plane which he named Glamorous Glennis, he flew it to a speed of 0.85 Mach on his first powered flight on 29 August. He encountered severe buffeting and sudden nose-up and -down trim changes during his next six flights. Then, during his eighth flight on 10 Oct., he lost pitch control altogether, as a shock wave formed along the hingeline of the X-1 elevator. He reached Mach 0.997 but without pitch control it would have been foolhardy to proceed. The X-1 had been designed with a moving horizontal tail and Capt Jack Ridley convinced Yeager that by changing its angle of incidence in small increments, he could control the craft without having to rely on the elevator. This had never been attempted at extremely high speeds but Yeager was game to give it a try on the next flight.
Ground test of the X-1’s power plant. The airplane was powered by a 4-chamber, 6,000-lb thrust XLR-11 rocket engine.
Famous photo shot by Bob Hoover from his FP-80 chase plane as Yeager and the X-1 accelerated past him on 14 October 1947.
On 14 Oct. he dropped away from the B-29, fired all four chambers of his engine in rapid sequence and bolted away from the launch aircraft. Accelerating upward, he shut down two chambers and tested the moveable tail as his Machmeter registered numbers of 0.83, .88 and 0.92. Moved in small increments, it provided effective control. He reached an indicated Mach number of 0.92 as he leveled out at 42,000 feet and relit a third chamber of his engine. The X-1 Glamorous Glennis rapidly accelerated to 0.98 Mach and then, at 43,000 feet, the needle on his Machmeter jumped off the scale.
Chuck Yeager had just crossed the invisible threshold to flight faster than the speed of sound. He attained a top speed of Mach 1.06 (700 mph). When Yeager’s achievement was finally declassified in June of 1948, he was quickly accorded celebrity status as “The Fastest Man Alive,” and was awarded the most prestigious honors in aviation. The words accompanying the Collier Trophy aptly summarized the magnitude of his flight: “This is an epochal achievement in the history of world aviation–the greatest since the first successful flight of the original Wright Brothers’ airplane, forty-five years ago.”
Yeager, standing on lift device that descended from the bomb bay of the B-29, just prior to entering the X-1’s cockpit.
In 1948, retired Commanding General of the U.S. Army Air Forces Henry H. “Hap” Arnold (in sunglasses) met Yeager on the lakebed for a briefing on his flights in the X-1.